How do lizards regrow their tails? This mystery had evaded scientists for years, but we now know the answer.
Researchers at the Keck School of Medicine at the University of Southern California have identified the essential cells involved in tail regeneration. You see, lizards can shed their tails, and they often do to escape predators. The lizard loses the tail and its original bone, and the new tail is made of softer cartilage.
USC researchers believe their discovery could help people overcome osteoarthritis. Affecting more than 32 million adults in the United States alone, osteoarthritis is the most common form of arthritis. Currently, the degenerative joint disease has no cure.
Lizards are in a class of their own. They are among the only higher vertebrates capable of regenerating cartilage that does not harden. Thus, lizards are the closest regenerating animal to mammals.
Fibroblasts are the tissue-building cells involved in the process. Researchers found that changes in gene activity among fibroblast cells allow the reptiles to rebuild cartilage. An immune cell known as a septoclast also helps allow the regeneration to occur.
Two key difference for humans remain. Unlike lizards, human tissue tends to scar, which ultimately prevents regeneration. Plus, humans cannot repair damaged cartilage once they reach adulthood.
The research team has successfully induced cartilage regeneration in lizards’ limbs, which do not regrow naturally.
If the same can happen for mice in the future, then someday, who knows? Our creaky knees and joints might be next in line for relief.